how to prep wall before skimming

[lidster]

hi,

trying to get the stairway hall wall ready for skimming over. 1930's semi.
steamed off all the layers of wallpaper and paint. scrubbed down with sugar soap solution. whats best for the small cracks I can see randomly all over the wall please... ive posted some pics and used a pencil to try and show how they run. If I tap on these areas they sound hollow...
will scrim taping be enough on the smaller areas with cracks? ive cut out one of them to show the crumbly cement/lime underneath.. large areas of the wall dont have cracks and dont have the same hollow sound so I assume I wouldnt have to knock this all off. these pics show the worst areas.

cheers

Untitled

• lidster
• 19 Feb 2014
• 1

Untitled

• lidster
• 19 Feb 2014
• 1

Untitled

• lidster
• 19 Feb 2014
• 1

 

[ree]

Why are you so keen to skim what appears to be a sound surface?
Paper will cover any minor blemishes - first fill and sand any gouges.

 

[Alastairreid]

The hollow stuff has to come off!

Cracks can be taped before skimming.